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Electrical Engineering
Electrical engineering is a field of engineering that deals with the study and application of electricity, electronics and electromagnetism.
23,056 Questions
How the work the ac in a 2001 qx4?
" AUTO" on your climate control activates Air Conditioning. Most efficient with recycled air option on.
"ECON" setting does not use A/C to cool, but only fan.
What is the functioning procedure of full wave rectifier by using SCRs?
"What is the functioning procedure of full wave rectifier by using SCRs?" "What is the functioning procedure of full wave rectifier by using SCRs?"
What is the maximum current capacity of 4 sq mm copper wire?
I can say it is 29 Amps.But again it depends on the cable length.The more the cable length is the less the current carrying capacity will be.
What is the forward voltage across diode based on its colors?
Diodes do not have color codes as far as I know. The "turn on" voltage is usually in the ballpark of .4 - .8 volts, and is dependent on the type of diode (germanium, etc.).
You may be referring to resistors. Look up in google resistor color code, and this should help you. There will be three colored lines, two are the resistance, the third is a scaling factor.
For example, if the first two colors match 82, and the third matches 3, the resistor is a 82 x 1000 = 8.2k ohm resistor.
There may also be a fourth color; this denotes the resistance tolerance (1, 2, 5, or 10 percent). If the tolerance is 10%, the above example may range from 8.2k + / 1 820 ohms.
What is the purpose of current limiting reactors in the power system?
Is used to reduce the short cct current levels within the ratings of the equipment on the load side of the reactor
What does form factor refer to?
Basically it means the shape of a device and how it fits into some application. For example, if I need a speciality small battery, I might describe it as having the form factor of a D-Cell battery, but a larger diameter.
How does change in frequency affect kva rating of a transformer?
diz is a controversial question,anyway i write my opinion
since E is directly proportional to f (E=4.44fBAT).....therefore the KVA changes on change of frequency..........
this is common thought,but what the controversial thing is why the current can't compensate the KVA rating to maintain it constant........
IN GATE book of G.K publishers the answer is IT DOES NOT AFFECT.
Can you measure AC current on a power cord?
Not very easily. A clamp on amp meter has to go around only one of the circuit conductors. If the clamp on meter is used around the power cord the two wires in the cord have a cancellation effect and the meter will read zero. If you can separate the load's wires that plug into the cord and clamp around that wire you will get a load amperage reading.
Explain how the induction motor gets loaded when the DC generator is loaded?
when the dc generator is loaded current will be drawn from it, therefore a back emf Will be generated, which opposes the motion of a generator, and hence, that opposition loads the three phase generator
Why the starting torque of a dc series motor is high?
load is heavier so starting torque is required
AnswerBecause the same current is passing through both the armature and field windings, the torque is proportional to the squareof the current. Since the starting current is alway high (no back emf), the torque will be very high indeed.
What is dynamic var compensation?
The reactive Power Compensation system that is Automatically able to adjust its reactive Power so that concerned system Power Factor is maintained within the desirable limits (Near Unity) is known as "Dynamic VAR Compnesation" system.
The Present day technology, known type of "Dynamic VAR Compensation" systems are:
Conventional Method:
* Contactor switched Capacitor Banks controlled by "Automatic PF controller / regulator". Also popularly known as "APFC system". Here capacitors are switched on/off depending upon the need automatically. Capacitors switched are frequently connected with series reactors for controlling harmonics through it or for switching transient suppression.
Static VAR compensation Method:
* Thyristor switched Capacitor Banks controlled by "Automatic PF controller / regulator". Also popularly known as "TSC system" or "RTPFC System (Real time PF correction)". Normally, the compensation time of such systems are much faster than conventional method. Here too, capacitor banks are frequently fitted with series reactors to control harmonics. The "zero differential voltage switching" of capacitor banks normally controls the switching transients.
* STATCON (Static Condenser) or STATCOM (Static Synchronous Compensator) is comparatively a new technology and offers smooth and fast reactive power (VAR) compensation by usage of Power Electronics based technology. Normally, the MOSFETs or IGBTs based inverter using sinusoidal PWM technology achieves the desired compensation either in capacitive and inductive reactive power.
* Thyristorised Static VAR compensator: This technology uses the thyristor switched or phase angle controlled reactors that are put in shunt with fixed capacitor. This is fairly an old technology and slowly due to economics and technology advantage of TSC system or STATCON / STATCOM system is not used recently.
All the above mentioned systems can be termed as "Dynamic VAR compensation" systems.
The "Fixed VAR compensation" which normally uses fixed capacitors / inductors that are permanantly connected on mains supply system (sometimes manually switched On/off) should not be confused as "Static VAR compensation" as word "Static" is used as adjective, which is for defining "type of technology" usage and not for "VAR".
What are the advantage of high transmission voltage?
Power houses uses high transmission voltage to supply places that are far away from the generation site. When in regards to distance the voltage is primary and the higher the voltage the greater the travel (using appropriate cable sizes etc). This voltage will suffer some loss during trans missioni but will arrive at its destination with a voltage drop that will not greatly affect the point of demand. keep in mind that this transmission is usually converted to Low voltage via a transformer before it is distributed to the end user.
Hope that helped:-)
What is the impedance of an 8 Henry inductor at 120 Hz?
Use the formula: reactance equals 2.pi times frequency times inductance.
Why voltage in transformer suddenly increases and then decreases suddenly?
In perfect condition, the voltage variations does not occur..
Due to failure causes, voltage variations will arise
50 Hz is the frequency of alternating current (ac) used by national electricity power services in Europe and several other world areas whilst 60 Hz is used in USA, Canada and many other countries in the world.
50 Hz means or specifies "50 cycles per second".
Hz is the international technical abbreviation for the scientific unit of frequency, the hertz.
The frequency remains the same as one cycle in the primary corresponds to one cycle in the secondary.
The stepdown voltage on the secondary as a ratio of the voltage on the primary will be the same as the ratio of turns in the primary to turns in the secondary.
The current in the secondary depends on two things: the current that the load is taking at the lower voltage of the secondary and the relative thickness of the wire in the secondary to the thickness of the wire in the primary.
ANSWER: A transformer does not step up/down a power source ever it does however step up/down the voltage related to the primary. A typical transformer will always have an efficiency loss. The frequency on the output will remain the same as the input. It is not true that the big wires will give you more current that would be true only if the iron core is increased accordingly. otherwise saturation will occur
What happens to the current in a circuit as a capacitor charges?
What happens to the current in a circuit as a capacitor charges depends on the circuit.
As a capacitor charges, the voltage drop across it increases. In a typical circuit with a constant voltage source and a resistor charging the capacitor, then the current in the circuit will decrease logarithmically over time as the capacitor charges, with the end result that the current is zero, and the voltage across the capacitor is the same as the voltage source.
How do you convert cooling capacity in Kw to hp?
Common air conditioning rating is giving in BTU/hr. You can converted the rating BTU/hr to kW by multiply BTU/hr with 0.0002931 kW/BTU.
You can also estimate the cooling capacity from energy supply, generally COP for air cool air conditioning is 3.5 kWcooling/kWelectricity
